The invention relates to a method for laying and interlocking panels, particularly via a fastening system consisting of positive retaining profiles provided on the narrow sides of the panels, which extend over the length of the narrow sides and are provided with joint projections or complementary joint recesses.
German utility model G 79 28 703 U1 describes a generic method for laying and interlocking floor panels with positive retaining profiles. These retaining profiles can be connected to each other by means of a rotary connecting movement. However, the disadvantage is that, in order to lay a second row of panels that is to be attached to a laid first row of panels, the second row first has to be completely assembled. The technical teaching to be taken from utility model G 79 28 703 U1 is that a first row of panels initially has to be laid ready horizontally and that a start is then made with a second panel in a second row, which has to be held at an angle and slid into a groove formed in the first panel row. The second panel has to be held at this angle, so that a third panel can be connected to the second panel. The same applies to the subsequent panels that have to be connected to each other in the second row. Only once all the panels of the second panel row have been pre-assembled in an inclined position can the entire second panel row be swung into horizontal position, this causing it to interlock with the first panel row. The unfavourable aspect of the laying method required for this panel design is the fact that several persons are required in order to hold all the panels of a second panel row in an inclined position for pre-assembly and then to jointly lower the second panel row into the laying plane. Another method for laying and interlocking panels is known from EP 0 855 482 A2. In this case, panels to be laid in the second row are again connected to the panels of a first row in an inclined position. Adjacent panels of the second row are initially interlocked with the panels of the first row, leaving a small lateral distance between them. In this condition, the panels of the second row can be displaced along the first row. Retaining profiles provided on the short narrow sides of the panels are pressed into each other by sliding two panels of the second row against each other. Disadvantageously, the retaining profiles are greatly expanded and elongated during this process. Even during assembly, the retaining profiles already suffer damage that impairs the durability of the retaining profiles. The retaining profiles designed and laid according to the teaching of EP 0 855 482 A2 are not suitable for repeated laying. For example, retaining profiles moulded from HDF or MDF material become soft as a result of the high degree of deformation to which the retaining profiles are subjected by the laying method according to EP 0 855 482 A2. Internal cracks and shifts in the fibre structure of the HDF or MDF material are responsible for this.
The object of the invention is thus to simplify the familiar method for laying and interlocking and to improve the durability of the fastening system.
According to the invention, the object is solved by a method for laying and interlocking rectangular, plate-shaped panels, particularly floor panels, the opposite long narrow sides and opposite short narrow sides of which display retaining profiles extending over the length of the narrow sides, of which the opposite retaining profiles are designed to be essentially complementary to each other, where a first row of panels is initially connected on the short narrow sides, either in that the complementary retaining profiles of a laid panel and a new panel are slid into each other in the longitudinal direction of the short narrow sides, or in that the retaining profile of a new panel is initially inserted in an inclined position relative to the laid panel having the complementary retaining profile of the laid panel and subsequently interlocked, both in the direction perpendicular to the connected narrow ends and in the direction perpendicular to the plane of the laid panels, by pivoting into the plane of the laid panel, the next step being to lay a new panel in the second row, in that the retaining profile of its long narrow side is initially inserted into the retaining profile of the long narrow side of a panel of the first row by positioning at an angle relative to it and subsequently pivoting into the plane of the laid panels, and where a new panel, the short narrow side of which must be interlocked with the short narrow side of the panel laid in the second row and the long narrow side of which must be connected to the long narrow side of a panel laid in the first row, is first interlocked with the panel of the second row at its short narrow end, the new panel then being pivoted upwards out of the plane of the laid panels along the long narrow side of a panel laid in the first row, where the panel of the second row that was previously interlocked with the new panel on the short narrow side is also pivoted upwards, at least at this end, together with the new panel, into an inclined position in which the long retaining profile of the new panel can be inserted into the complementary retaining profile of the panel laid in te first row and, after insertion, the inclined new panel and the panel interlocked with the new panel on a short narrow side in the second row are pivoted into the plane of the laid panels.
According to the new method, panels to be laid in the second row can be fitted by a single person. A new panel can be interlocked both with panels of a first row and with a previously laid panel of the second row. This does not require interlocking of the short narrow sides of two panels lying in one plane in a manner that expands and deforms the retaining profiles.
The last panel laid in the second row can be gripped by its free, short narrow end and can be pivoted upwards into an inclined position about the interlocked, long narrow side as the pivoting axis. The panel is slightly twisted about its longitudinal axis in this process. The result of this is that the free, short narrow end of the panel is in an inclined position and the inclination decreases towards the interlokked, short narrow end of the panel. Depending on the stiffness of the panels, this can result in more or less strong torsion and thus in a greater or lesser decrease in the inclination. In the event of relatively stiff panels, the inclination can continue through several of the previous panels in the second row.
When laying, it is, of course, not necessary for the first row to be laid completely before making a start on laying the second row. During laying, attention must merely be paid to ensuring that the number of elements in the first row is greater than that in the second row, and so on.
The method can be realised particularly well when using thin, easily twisted panels. The inclination of a thin panel located in the second row decreases over a very short distance when subjected to strong torsion. The non-twisted remainder of a panel, or of a panel row, located in the laying plane, is securely interlocked. Only on the short, inclined part of the last panel of the second row can the retaining profiles of the long narrow sides become disengaged during the laying work. However, they can easily be re-inserted together with the new panel attached at the short narrow side.
A particularly flexible and durable design is one consisting of rectangular, plate-shaped panels that display complementary retaining profiles extending over the length of the narrow sides on narrow sides parallel to each other, where one retaining profile is provided in the form of a joint projection with a convex curvature and the complementary retaining profile in the form of a joint recess with a concave curvature, where each joint projection of a new panel is inserted into the joint recess of a laid panel, expanding it only slightly, and the new panel is finally interlocked by pivoting into the plane of the laid panel. The deformation of the retaining profiles required for laying and interlocking is considerably smaller than with retaining profiles that have to be pressed together perpendicular to their narrow sides in the laying plane. Advantageously, the joint projection does not protrude from the narrow side by more than the thickness of the panel. In this way, another advantage lies in the fact that the retaining profile can be milled on the narrow side of a panel with very little waste.
When laid, the retaining profiles of the long narrow sides of two panels, which can also be referred to as form-fitting profiles, form a common joint, where the upper side of the joint projection facing away from the substrate preferably displays a bevel extending to the free end of the joint projection, and where the bevel increasingly reduces the thickness of the joint projection towards the free end and the bevel creates freedom of movement for the common joint.
The design permits articulated movement of two connected panels. In particular, two connected panels can be bent upwards at the point of connection. If, for example, one panel lies on a substrate with an elevation, with the result that one narrow side of the panel is pressed onto the substrate when loaded and the opposite narrow side rises, a second panel fastened to the rising narrow side is also moved upwards. However, the bending forces acting in this context do not damage the narrow cross-sections of the form-fitting profiles. An articulated movement takes place instead.
A floor laid using the proposed fastening system displays an elasticity adapted to irregularly rough or undulating substrates. The fastening system is thus particularly suitable for panels for renovating uneven floors in old buildings. Of course, it is also more suitable than the known fastening system when laying panels on a soft intermediate layer.
The design caters to the principle of xe2x80x9cadapted deformabilityxe2x80x9d. This principle is based on the knowledge that very stiff, and thus supposedly stable, points of connection cause high notch stresses and can easily fail as a result. In order to avoid this, components are to be designed in such a way that they display a degree of elasticity that is adapted to the application, or xe2x80x9cadapted deformabilityxe2x80x9d, and that notch stresses are reduced in this way.
Moreover, the form-fitting profiles are designed in such a way that a load applied to the upper side of the floor panels in laid condition is transmitted from the upper-side wall of the joint recess of a first panel to the joint projection of the second panel and from the joint projection of the second panel into the lower-side wall of the first panel. When laid, the walls of the joint recess of the first panel are in contact with the upper and lower side of the joint projection of the second panel. However, the upper wall of the joint recess is only in contact with the joint projection of the second panel in a short area on the free end of the upper wall of the joint recess. In this way, the design permits articulated movement between the panel with the joint recess and the panel with the joint projection, with only slight elastic deformation of the walls of the joint recess. In this way, the stiffness of the connection is optimally adapted to an irregular base which inevitably leads to a bending movement between panels connected to each other.
Another advantage is seen as lying in the fact that the laying and interlocking method according to the invention is more suitable for repeated laying that the known methods, because the panels display no damage to the form-fitting profiles after repeated laying and after long-term use on an uneven substrate. The form-fitting profiles are dimensionally stable and durable. They can be used for a substantially longer period and re-laid repeatedly during their life cycle.
Advantageously, the convex curvature of the joint projection and the concave curvature of the joint recess each essentially form a segment of a circle where, in laid condition, the centre of the circle of the segments of the circle is located on the upper side of the joint projection or below the upper side of the joint projection. In the latter case, the centre of the circle is located within the cross-section of the joint projection.
This simple design results in a joint where the convex curvature of the joint projection is designed similarly to the ball, and the concave curvature of the joint recess similarly to the socket, of a ball-and-socket joint, where, of course, in contrast to a ball-and-socket joint, only planar rotary movement is possible and not spherical rotary movement.
In a favourable configuration, the point of the convex curvature of the joint projection of a panel that protrudes farthest is positioned in such a way that it is located roughly below the top edge of the panel. This results in a relatively large cross-section of the joint projection in relation to the overall thickness of the panel. Moreover, the concave curvature of the joint recess offers a sufficiently large undercut for the convex curvature of the joint projection, so that they can hardly be moved apart by tensile forces acting in the laying plane.
The articulation properties of two panels connected to each other can be further improved if the inside of the wall of the joint recess of a panel that faces the substrate displays a bevel extending up to the free end of the wall and the wall thickness of this wall becomes increasingly thin towards the free end. In this context, when two panels are laid, the bevel creates space for movement of the common joint. This improvement further reduces the amount of elastic deformation of the walls of the joint recess when bending the laid panels upwards.
It is also expedient if the joint recess of a panel for connecting to the joint projection of a second panel can be expanded by resilient deformation of its lower wall and the resilient deformation of the lower wall occurring during connection is eliminated again when connection of the two panels is complete. As a result, the form-fitting profiles are only elastically deformed for the connection operation and during joint movement, not being subjected to any elastic stress when not loaded.
The ability also to connect the short narrow ends of two panels in articulated fashion benefits the resilience of a floor covering.
The form-fitting profiles preferably form an integral part of the narrow sides of the panels. The panels can be manufactured very easily and with little waste.
The laying method is particularly suitable if the panels consist essentially of an MDF (medium-density fibreboard), HDF (high-density fibreboard) or particle board material. These materials are easy to process and can be given a sufficient surface quality by means of cutting processes, for example. In addition, these materials display good dimensional stability of the milled profiles.